Pollutant recovery system

ABSTRACT

A system is described for removing a pollutant from the surface of water wherein the pollutant is confined to a recovery area and is directed to a recovery station by a plurality of linked booms. A particulate, floatable sorbent material is continuously distributed over the pollutant confined in the recovery area as it moves to the recovery station. The sorbent material is distributed in sufficient quantity to adsorb substantially all of the pollutant prior to its arrival at the recovery station. At the recovery station, recovery means are employed for removing the sorbent material and the adsorbed pollutant from the water surface.

[ May 22, 1973 [54] POLLUTANT RECOVERY SYSTEM [76] Inventor: James J.Zerbe, 2323 5th Avenue,

San Rafael, Calif.

22 Filed: Jan. 15, 1971 21 Appl.No.: 106,844

2/1971 lO/l97l McNeely .2 10/242 Valdespino ..2 10/242 PrimaryExaminer-Samih N. Zaharna Assistant Examiner-Thomas G. WyseAttorney-Fitch, Even, Tabin & Luedeka 57 ABSTRACT A system is describedfor removing a pollutant from the surface of water wherein the pollutantis confined to a recovery area and is directed to a recovery station bya plurality of linked booms. A particulate, floatable sorbent materialis continuously distributed over the pollutant confined in the recoveryarea as it moves to the recovery station. The sorbent material isdistributed in sufficient quantity to adsorb substantially all of thepollutant prior to its arrival at the recovery station. At the recoverystation, recovery means are employed for removing the sorbent materialand the adsorbed pollutant from the water surface.

10 Claims, 6 Drawing Figures Patented May 22, 1973 3,734,294

2 Sheets-Sheet 2 INVENTOR. JAMES J. ZERBE ATTORNE Y5 POLLUTANT RECOVERYSYSTEM This invention relates to the removal of a pollutant from thesurface of water and, more particularly, to a system for removingpollutant from the surface of water and to recovery apparatus for usetherein.

The potential ecological damage from massive ocean surface pollution hasincreased in proportion to the increasing use and size of tankers anddevelopment of undersea oil fields. Although some petroleum products maybe effectively removed from the oceans surface by burning, others,particularly crude oil, are not easily ignited. Detergents and otherdispersal agents can have as serious ecological consequences when usedextensively to clean up surface pollutants as the pollutants themselves.Coagulant chemicals for causing the surface pollutant to coagulate andsink may also be unsat isfactory due to the adverse ecological effectson sea bottom life from extensive coating of undersea surfaces.

Although apparatus has been designed for removing surface pollutants,such apparatus has not been readily adaptable to operation in a recoverysystem of the scale necessary to handle the extensive surface pollutionresulting from off-shore oil well blow-outs or marine disasters. Inaddition, such apparatus has not been readily capable of handling thewidely varying conditions which may prevail in the vicinity ofwidespread ocean surface pollution.

In designing an overall system for recovering ocean surface pollutants,sufficient flexibility should be built into the system to take intoaccount the above mentioned variations in conditions. Thus, asatisfactory pollutant removal system is preferably capable of handlingvariations in the depth and area of the pollutant, wind direction andvelocity, wave height and frequency, and tides and/or surface currents,the latter particularly in estuaries and other confined places.

Not only must the overall pollutant removal system be capable ofoperating under the above variations in conditions, but the particularapparatus utilized for the recovery of the pollutant must also becapable of operating subject to the above variations. Moreover, therecovery apparatus itself must be capable of picking up for storing, ona continuous basis, large quantities of the surface pollutant.Furthermore, recovery should be at a rate which is sufficiently fast asto be capable of exceeding the rate at which the pollutant isreplenished, particularly in the case of an off-shore oil well blow out.

In order to confine the surface pollutant to a recovery area and thusfacilitate recovery of the pollutant by the recovery apparatus, thepollutant removal system may employ a linkage of floats or boomssurrounding the pollutant. The use of floats or booms for this purposeis well known in the art. Nevertheless, the development of asatisfactory pollutant removal system also necessitates the use of acontainment system capable of operating under the above mentionedvariations in conditions without allowing the confined pollutant toescape from the recovery area. Escape of pollutant may occur by thepollutant passing over the top of the floats or booms due to inadequateresponse of the booms or floats to wave or wind action. Under someconditions, particularly surface current or high winds, the surfacepollutant may flow underneath the floats or booms and such anoccurrence, of course, should be prevented for satisfactory systemoperation. Finally, the design of a containment apparatus for use in apollutant removal system of necessity must deal with such problems asundue rotation of the booms or floats, corrosion of the various partsincluding the connecting members thereof, and jackknifing of the linkedbooms or floats.

Accordingly, it is an object of the present invention to provide animproved system for removing a pollutant from the surface of water.

Another object of the invention is to provide an im proved pollutantremoval system capable of taking into account variations in the size ofthe pollutant spill, the direction and velocity of the wind in the area,the wave action, and tides or surface currents.

A further object of the invention is to provide improved pollutantrecovery apparatus for use in the above system.

Other objects of the invention will become apparent to those skilled inthe art from the following description taken in connection with theaccompanying drawings wherein:

FIG. 1 is a plan view illustrating the use of a recovery systemconstructed in accordance with the invention;

FIG. 2 is a plan view of apparatus used in the system of FIG. 1;

FIG. 3 is a side view of the apparatus illustrated in FIG. 2;

FIG. 4 is an end view of the apparatus illustrated in FIG. 2;

FIG. 5 is a plan view of further apparatus used in the system of theinvention; and

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 5.

Very generally, the system of the invention comprises a plurality oflinked booms 11 for positioning downwind or down-current from apollutant source 12 (or 21 or 22) to confine the pollutant to a recoveryarea 13 and to direct the pollutant to a recovery station 14.Distributing means 16 are provided for continuously distributing aparticulate, floatable, sorbent material over the pollutant confined inthe recovery area as it moves toward the recovery station. Theparticulate sorbent material is distributed in sufficient quantity toadsorb substantially all of the pollutant prior to its arrival at therecovery station. Recovery means 17 are provided at the recovery stationfor continuously removing the sorbent material and the adsorbedpollutant from the water surface.

Referring now more particularly to FIG. 1, the system of the inventionis illustrated in connection with an off-shore drilling structure 12 foran oil well or oil wells. The drilling structure constitutes the sourceof pollutant such as would occur in the event of a defective well orwell blow-out. Several other sources 21 and 22 of pollutant in thevicinity of the platform 12 are also shown. Overall containment of theoil spill or surface pollutant is provided by a surrounding barrierconsisting of a plurality of linked booms 23 secured and anchored in anysuitable manner. Preferably, the booms 23 are secured and anchored asshown and described in my copending application Ser. No. 57,121.

In the even of an oil well blow-out or other leak in the vicinity of thedrill structure 12, the surface of the ocean in such vicinity willbecome covered with oil. Depending upon wind, current, or both, the oilwill move in a direction away from the source and gradually spread out.This is indicated in the plan view of FIG. 1.

The linked booms 11 are arranged to contain the oil within the recoveryarea 13 and todirect it to the re-' covery station 14. Inthe illustratedsystem, this is accomplishedby arranging the booms in a semicirculararrangement suitably anchored at the outermost ends;

not shown, beyond the farther outer limits of the oil 1 spill or spillssuch as beyond the path of the oil emanating from the sources 21 and 22.Because of the curvature of the booms, the oil from the sources 21 and22 is confined and directed toward the recovery area 13 and merges withthe oil from the platform 12. The semicircular portion of the boomarrangement 11 is open towards the recovery area and the booms areredirected by suitable anchoring, not shown, to funnel the oil in therecovery area towards the recovery station 14. Although the particulararrangement illustrated in FIG. 1 provides a satisfactory means ofaccomplishing the confinement and directing of the surface pollutant,other boom arrangements may be used consistent with the invention.

Deployment of the systems of booms illustrated in FIG. 1 down-wind ordown-stream may be accomplished prior to the actual occurrence of apolluting situation. Thus, protective arrangements of booms may beplaced around drilling areas with the placement of the anchors, sinkerblocks and anchorage chain or cable, and buoy floats occurring prior toany oil spill. The boom units may be assembled from barges on site ormay be assembled in shore and towed to the site of their placement.

It is known that floatable, particulate, sorbent material may be spreadupon oil or other pollutant to expedite recovery of the pollutant fromthe surface of water. For example, granulated or ground polyurethaneapplied to an oil slick is capable of picking up the oil at a ratio of28 pounds to 1 in 2 hours. The polyurethane used in such tests was notsaturated and no oil was remaining on the water after removal of thesorbent. The properties of various types of sorbent material on varioustypes of test oils are set forth on page 43 of the July 1970 issue ofOcean Industry.

In the system of the invention, pollutant in the recovery area is seededwith a particulate, floatable sorbent material, such as granulated orground polyurethane. The seeding is such that the sorbent material isdistributed over the entire surface of the pollutant in the recoveryarea so that all the pollutant passing therethrough on its way to therecovery station 14 comes in contact with the sorbent material. Theamount of sorbent material distributed is such as to be greater than theamount at which saturation would take place. Thus, there is anoverabundance of sorbent material present in the recovery area afterseeding to insure that no oil or pollutant remains after the pick-upoperation described subsequently.

The means 16 for distributing the sorbent material comprise seeder unitsdeployed at the ends of tethers 24. Two seeder units 16 and two tethers24 are illustrated. The details of the seeder units are describedsubsequently. A pivot platform 26 is provided at the corner between thefunnel section of the booms 11 and the semicircular sections thereof.Each pivot platform is anchored on four sides for stable positioning andthe tethers 24 are attached thereto. A supply or tender barge 27 isanchored near each of the pivot platforms for supplying sorbent materialto the distributing means through flexible ducts as will'be described.

and means are provided for propelling the seeder units 16 reciprocallyabout an arcuate path at the ends of their tethers 24.

Referring now more particularly to FIGS. 2 and 3, a seeder unit isillustrated in detail. A flexible duct 31 connects the seeder unit withthe pivot platform 26, as will be explained, and provides a supply ofpressurized air with entrained sorbent material to the seeder unit. Thesorbent material is then sprayed out through a front nozzle 32 and twoside nozzles 33 and 34. The side nozzles 33 and 34 are angled away fromthe front nozzle at about The nozzles emanate from a common manifold 36to which the flexible duct 31 is attached by suitable mounting flanges37. The nozzles extend from the tube 36 substantially horizontally andthe tube 36 is supported in a horizontal position by a pair of verticalsupports 38 and 39 with mounting clamps 41 and 42 at their upper ends. Apair of support struts 43 and 44 angle outwardly from the verticalsupport 38 to provide rigidity to the mounting arrangement. The ends ofthe struts 43 and 44 are bolted to the upper surface of a horizontalplatform or deck 46.

The horizontal platform 46, which provides the base for the seeder unitis floated on a pair of pontoons 47 and 48 suitably secured to theunderside of the platform 46 beneath a pair of horizontal crossbeams 49,only one of which is visible. Positioning of the pontoons and mountingof the nozzles are arranged so as to provide stability to the unit as itfloats in the water. The arrangement of the nozzles enables a wide swathor coverage of sorbent material for each reciprocation of the unit inits arcuate path.

In order to propel the seeder unit 16, each seeder unit is provided withan outboard motor 51 mounted at one end of the platform 46 in a motorwell 52 formed therein. The outboard motor 51 is oriented to providetension on the tether 24 at all times such that the seeder unit willmove in an arcuate path at the very end of the tether with a center atthe pivot platform 26. Automatic cyclcing is provided by a suitablemechanical reversing linkage comprising links 53 and 54, an over centertoggle device 56, and a trip bar 57. The over center toggle device 56may comprise a suitable cam and coil spring to provide a snap action toreverse the linkage from the position shown to the opposite side andthereby change the direction of the outboard motor 51. The trip bar 57includes a pair of downwardly extending sections 58 on each side whichare tripped by the booms as the device reaches the extremities of itsarcuate travel. This changes the direction of the outboard motor andstarts the seeder unit in the op posite direction in its arcuate path.

Turning now to FIG. 4, the pivot platform 26 is illustrated in a sideelevation. The pivot platform 26 is ,floated on three pontoons 61, 62and 63 extending extending from near the top of the vertical struts 67back down to the deck. A bracket 69 at the upper end of the strut 67 anda bracket 71 near the lower end of the'vertical strut 67 secures a tube72 in a vertical position. The tube 72 has an upper swivel elbow 73which is attached to the opposite end of the duct 3l..from the end ofthe duct attached to the corresponding seeder unit 16. The duct 31 isflexible and allows the seeder unit to move in its arcuate path withrespect to the pivot platform 26 while maintaining communicationtherewith to transfer air entrained sorbent material to the seeder unit.The lower end of the tube 72 contains another elbow section 74 whichextends at an angle from the bracket 71 downwardly to extend outward ofthe platform 26. The lower end of the elbow 74 is attached by a flexibleduct, not shown, similar to the duct 31 to a support tender 27 whichsupplies pressurized air and sorbent material. The air entrained sorbentmaterial is then transferred through the elbow 74 through the tube 72and the elbow 73 through the duct 31, the manifold 36 and then issuesforth from the nozzles 32, 33 and 43 to be distributed overthepollutant.

In order to stabilize the pivot platform 26, a suitable anchorage isemployed, not shown. Preferably, the anchorage is a four-way anchorageto maintain the pivot platform in a fixed position relative to thesource of the pollutant. For stability, a beam 76 extends downwardlyfrom the pivot platform and a counterweight 77 is supported on the endof the beam 76. The cable 24 is secured to the upper surface of thecounterweight 77 by suitable means, not shown.

In FIGS. 5 and 6, the recovery device 17 is shown in detail. Therecovery device 17 comprises a pair of pontoons 81 and 82 arrangedparallel with each other and supporting a frame. The frame is comprisedof a pair of forward struts 83 and 84 on the pontoons 81 and 82,respectively, which extend upwardly from the pontoons and are angledslightly backward towards the rear of the device. A similar pair ofupright struts 85 and 86 extend from the pontoons 81 and 82,respectively, and extend at an angle forwardly. The upper ends of thestruts 83 and 85 are connected by a cross bar 87 and the upper ends ofthe struts 84 and 86 are connected by a horizontal crossbar 88. Thelower ends of the struts 83 and 84 adjacent the pontoons 81 and 82,respectively, are connected by a horizontal reinforcing bar 89. Theforward ends of the pontoons 81 and 82 are chained to the ends of thefunnel section booms 11. Suitable means, not shown, are provided betweenthe ends of the booms 11 and the ends of the pontoons 81 and 82 toprevent leakage of pollutant.

Upright flanges 91 and 92 are mounted on the top of the pontoons 81 and82, respectively. A stub shaft 93 extends from each of the flanges 91and 92 and the stub shafts support, by suitable bearings not shown, apair of support discs 94 and 96 spaced from and parallel with eachother. A series of troughs or buckets are mounted between the discs 94and 96 and are distributed circumferentially about the discs. As may beseen in FIG. 6, the troughs are shaped in a manner of scoops with theirouter lips extending radially outward of the discs 94 and 96.

Drive for the rotary arrangement of the troughs 97v and the supportingdiscs 94 and 96 is provided by a suitable drive motor 101 and a drivechain 102 and drive sprocket 103, coupled to the disc 94. Rotation ofthe apparatus is in the direction of arrows in FIG. 6, i.e., clockwise,so that the scoops move with their open sides coming up underneath themat of sorbent and adsorbed pollutant. The bottom surfaces 104 of thetroughs are porous such as with a galvanized screen enabling the lessviscous water captured in the troughs to quickly escape as the troughsmove upwardly, but preventing the sorbent-pollutant combination frompassing out of the troughs.

As may be seen in FIG. 6, the troughs move upwardly and, since they arerigidly attached to the discs 94 and 96, begin to tip, discharging theircontents. A collection tray 106 is positioned between the inner ends ofthe stub shafts 93 at a position to receive the contents of the troughsas they discharge when they are tipped upright by the rotation of theapparatus. This is illustrated in FIG. 6. In order to facilitatedischarge of the contents of the troughs into the collection tray 106, apair of conduits 107 and 108 are provided extending between thecrossbeams 87 and 88. The conduits are equipped with a plurality ofnozzles 109 spaced along their length and pointing downwardly. Suitablemeans, not shown, supplies hot water or possibly a detergent mixture tothe conduits 107 and 108 to be discharged through the nozzles 109. Thenozzles are aimed at the troughs in order to facilitate the release ofthe contents thereof. Due to the porosity of the bottoms 104 of thetroughs, the spray liquid, under pressure, can pass into the interior ofthe troughs and easily discharge their contents into the collection tray106.

The collection tray 106 is provided with a discharge orifice 111 at oneend thereof. The discharge orifice passes through an opening in the disc94 and is connected through a suitable flexible conduit 112 to a pump ina support tender 113 (see FIG. 1). The support tender is equipped withsuitable pumping capacity to withdraw the contents of the collectiontray 106 and thus effect continuous removal of the pollutant.

In the illustrated embodiment, the recovery apparatus 17 is shown usedin connection with a retention system as shown and described in theaforesaid copending application. As may be seen in FIG. 6, one of thebooms 23 in the outer ring of booms seen in FIG. 1 is provided with ahigh pressure vessel 116 mounted in outrigger fashion on the pollutantside of the boom. The high pressure vessel is for supplying compressedair to an air release system, not shown, used in conjunction with theboom. The system is described more fully in the aforementioned copendingapplication. The high pressure vessel 116 is connected to the ends ofthe boom by a pair of outer struts 117 and 118 and by a central strut119. Braces 121 and 122 extend from the boom 23 to the juncture betweenthe tank 116 and the struts 117 and 118. The tank is pressurized througha line 123 from the support tender 113 (FIG. 1). Air from the tank 116is used to assist in preventing flow of pollutant under the boom 23, asdescribed in detail in the aforesaid copending application. The pontoons81 and 82 are attached to the juncture between the struts 117 and 118and the tank 116 by pivotal hinges 124 and 125, respectively.

The detailed construction of the booms 23 are described in the aforesaidcopending application and will not be discussed in detail herein. Inorder to increase the surface area and provide a barrier offeringresistance to escape of the oil or pollutant from the recovery area, thebooms 23 are each provided with an upper fin 131 and a lower steel platekeel 132. The fin 131 of reinforced polystyrene is chemically bonded orwelded to the skin of the boom 23 and is formed with a splash guard 133to prevent splashing of the pollutant over the boom. The keel 132 isbolted to a flange 134 which depends from the underside of the boom 23.The spaces neoprene skirts 136 and 137 as described in greater detail inthe aforesaid copending application. The lower edge of thekeel 132 isprovided with a conduit 137 to which a line 138 is connected from thepressurized tank 116. Air under pressure is supplied to theconduit 137and is released in a manner to prevent flow of oil under the keel asdescribed in the aforesaid copending application.

To insure that the sorbent-pollutant mat will not escape beneath theauxiliary boom, a small meshed fabric net 141 2 inch mesh for example)is attached to the keel of the boom segments as shown in FIG. 1. Thebottom of the net consists of a tube in which a cable or nylon line isthreaded with ends terminating at the two pivot platforms shown inFIG. 1. By attaching the mid portion of the tube at the bottom of thenet to the recovery device 17, the ends may be tensioned so thatdrawstring action shrinks the base of the net and prevents any sorbentmaterial from escaping underneath the booms by undertow. The net issufficiently porous as to allow full flow of current withoutrestriction.

It may therefore be seen that the present invention provides an improvedsystem for removing pollutant from the surface of water and improvedrecovery apparatus for use therein. The system is capable of handlinglarge amounts of surface pollutant and of recovering it very quickly.The system is economical and is adaptable to a wide variety ofconditions.

Various modifications of the invention shown and described herein willbecome apparent to those skilled in the art from the foregoingdescription and accompanying drawings. Such modifications are intendedto fall within the scope of the appendant claims.

What is claimed is:

1. A system for removing a pollutant from the surface of water,comprising, a plurality of linked booms for positioning down-wind ordown-current to confine the pollutant to a recovery area, said boomsbeing arranged in a configuration which directs the pollutant to arecovery station, distributing means positioned a substantial distancefrom said recovery station for continuously distributing a particulatefloatable sorbent material over the pollutant confined in the recoveryarea as it moves to the recovery station, said distributing meansadapted to provide sorbent material in sufficient quantity to adsorbsubstantially all of the pollutant prior to its arrival at the recoverystation, and recovery means at the recovery station for continuouslyremoving the sorbent material and the adsorbed pollutant from the water.surface, said recovering means including a rotatable support and aplurality of scoops mounted thereon, said scoops each having at least apart of a porosity to allow water to pass out of said scoops whileretaining said sorbent material and adsorbed pollutant, and sorbentremoval means for removing said sorbent material and adsorbed pollutantfrom said scoops.

2. A system according to claim 1 wherein said scoops are rigidly mountedto said support so that they tip at the top of the rotational path, andwherein said sorbent removal means include a collection tray positionedto receive the contents of said scoops as they tip.

3. A system according to claim 2 wherein said sorbent removal meansfurther include means for spraying hot water on said scoops as they tipabove said collection tray to facilitate discharge of the contents ofsaid scoops.

4. A system according to claim 2 wherein means are provided fortransferring material from said collection tray to a storage vessel.

5. A system according to claim 1 wherein said recovery means include afloatable base, and wherein said support is mounted on said floatablebase.

6. A system according to claim 5 including hinged means coupling saidfloatable base to at least one of said linked booms.

7. A system according to claim 1 wherein said distributing means includeat least one flexible duct having a discharge end, and means forsupplying air entrained particulate, floatable, sorbent material to saidduct to be discharged therefrom at the recovery area from said dischargeend.

8. A system according to claim 7 wherein said distributing means includea floatable support for said discharge end for said flexible duct.

9. A system according to claim 8 wherein said distributing means includemeans for moving said floatable support repetitively to vary thedirection in which entrained sorbent material is discharged from saidduct.

10. A system according to claim 9 wherein said moving means includemeans comprising a tether for securing said floatable support to atleast one of said linked booms, propelling means on said floatablesupport oriented to maintain tension in said tether, and means forvarying the direction of said propelling means to cause said floatablesupport to reciprocate in its motion.

1. A system for removing a pollutant from the surface of water,comprising, a plurality of linked booms for positioning down-wind ordown-current to confine the pollutant to a recovery area, said boomsbeing arranged in a configuration which directs the pollutant to arecovery station, distributing means positioned a substantial distancefrom said recovery station for continuously distributing a particulatefloatable sorbent material over the pollutant confined in the recoveryarea as it moves to the recovery station, said distributing meansadapted to provide sorbent material in sufficient quantity to adsorbsubstantially all of the pollutant prior to its arrival at the recoverystation, and recovery means at the recovery station for continuouslyremoving the sorbent material and the adsorbed pollutant from the watersurface, said recovering means including a rotatable support and aplurality of scoops mounted thereon, said scoops each having at least apart of a porosity to allow water to pass out of said scoops whileretaining said sorbent material and adsorbed pollutant, and sorbentremoval means for removing said sorbent material and adsorbed pollutantfrom said scoops.
 2. A system according to claim 1 wherein said scoopsare rigidly mounted to said support so that they tip at the top of therotational path, and wherein said sorbent removal means include acollection tray positioned to receive the contents of said scoops asthey tip.
 3. A system according to claim 2 wherein said sorbent removalmeans further include means for spraying hot water on said scoops asthey tip above said collection tray to facilitate discharge of thecontents of said scoops.
 4. A system according to claim 2 wherein meansare provided for transferring material from said collection tray to astorage vessel.
 5. A system according to claim 1 wherein said recoverymeans include a floatable base, and wherein said support is mounted onsaid floatable base.
 6. A system according to claim 5 including hingedmeans coupling said floatable base to at least one of said linked booms.7. A system according to claim 1 wherein said distributing means includeat least one flexible duct having a discharge end, and means forsupplying air entrained particulate, floatable, sorbent material to saidduct to be discharged therefrom at the recovery area from said dischargeend.
 8. A system according to claim 7 wherein said distributing meansinclude a floatable support for said discharge end for said flexibleduct.
 9. A system according to claim 8 wherein said distributing meansinclude means for moving said floatable support repetitively to vary thedirection in which entrained sorbent material is discharged from saidduct.
 10. A system according to claim 9 wherein said moving meansinclude means comprising a tether for securing said floatable support toat least one of said linked booms, propelling means on said floatablesupport oriented to maintain tension in said tether, and means forvarying the direction of said propelling means to cause said floatablesupport to reciprocate in its motion.